Telephone system



Feb. 10, 1931. c. R. BROOKS TELEFHONE SYSTEM Fi led Jan. 2. 1929 Xwol Inuan ar' Charles H.5ruuks Patented Feb. 10,

UNITED STATES,

PATENT oFicE CHARLES R. BRoo s, or CHICAGQVIIQLYINOIS, Assrenos To RESERVE 1 HOLDING COM- PANY, or KANSAS CITY, MISSOURI, :A CORPORATION-OF.DELAWARE TELEP ONE SYSTEM Application filed January 2, 1929. 7 Serial No. ;329,692.

The present invention relates to telephone systems in general, but is concerned moreparticularly with telephone systems wherein connections are set up over toll lines and through automatic switching apparatus, and the broad general object may be stated as the provision of new and improved arrangements whereby the association withand the disassociation from a tollline ofa switch-controlling device may be made in an eflicient manner.

The present invention is concerned more particularly with toll boards built initially for manual'toll and service only and which are tobe altered to enable automatic switchingapparatus to be controlled over the toll lines to set up tollconnections; c In certain respects this invention maybe considered an improvement on the disclosure in the U. S. patent to Wicks 1,593,737, granted July 22, 1926, with particular reference to the disclosure in Fig. 1 of'the patent;

'A special feature of the present invention isthat responsive to theoperation of a SKU- 'ple push button individual-to a toll line at anqoperators position the callingdevice at her position is automatically connected in operative relation to the toll line, and when the push button is again operated the calling device is automatically disconnected.

Another feature of the invention is that at a multiple switchboard whereat each toll line appears a plurality of times the operation of a push button individualto a toll line at the second position does not interfere with the connection of a calling device at the first position; the second operator can neither intrude her calling device upon the connection nor cause the first, calling device to be disconnected.

Further features of the invention which are mainly subordinate to the foregoing, will appear upon a further perusal of the specification in connection withthe accompanying drawing comprising a single sheet. 7

Referring now to the drawing, two positions, position 1 and position X, of a multiposition toll board are indicated and they are assumed to be the first and last positions, respectively. The connections of the toll lines TL at the toll board are indicated.

Atth'e position X, there is shown a connecting relay, 3, and actuating push button P2, an indicating lamp L2, a multiple jack MJ2, an answering lamp AL, and an answering jack AJ. The foregoing equipment is all'individual to the toll line TL at the position X. In addition, 'at't-he position X there is shown the calling device CD2, this calling device being common to all the toll lines at the position. It will be noted upon inspection that the equipment at position 1 individual tot-he toll TL is similar to the equipment at position X except that no answering lamp and answering jack are provided, this being in accordance with the standard practice to provide an answering jack at only one position while multiple jacks appear at several positions. The equipment to the rightof the dotted line AB is common to the several positions in which the toll line is multipled. 1

The invention having been described genera1ly,'a detailed description of the operation of the apparatus shown willnow be given.

Handling an incoming call It will now be assumed that an incoming call is received over the toll line TL. Connection may be made to the distant end of the toll line TL either manually or automatically as disclosed in the Wicks patent hereinbefore referred to. After the connection is made at the distant end, ringing current is applied at the distant end of the toll line TL and is received at the end of the toll line TL shown in the drawing and is repeated through the windings of the repeating coil and through contacts of the cut-oil relay 52 and the associated condenser to the ring-up relay 51 shown in'the'lower right-hand corner of the drawing. Upon "operating, the ring-up relay 51 becomesmechanically looked under the control of the armature of the 'the answering lamp AL.

From this point the connection is handled in the usual manner and as explained in l/Vicks patent.

Outgoing call from position 1 It will now be assumed thatthe operator at position 1 desires to extend an outgoing connectlon over a toll line suchas the, toll line TL and that the toll line TL is idle as indicated bythe usual tip busy test. The operator accordingly inserts the plug of the cord in use into the multiple jack MJ 1 whereupon the sleeve relay loperates through the sleeve of the plug and jack and closes a circuit for the cut-oil relay 52 by way of resistance 10. At its inner armature, relay 4: places battery through resistance 8 on conductor 11 by way of contacts of relays 3 and 2138 well as similar contacts at intermediate positions. Placing battery on-cond-uctor 11 sets up a current flow over the two sides of the toll line TL in parallel, preparing the distant automatic switching apparatus for operation'in the usual manner.

In order to associate her calling device CD1 with the trunk line TLl, the operator momentarily operates the push button P1, closing a circuit at the upper contacts of the, push button through both'windings of relay 2 in series, which circuit includes contacts of relays 5 and 4: and also the resistance '9. Upon operating, relay 2 closesa locking circuit through its upper winding'alone, by passing the lower winding ofthe relay so as to lower the poten tial applied to conductor 11 by way of the resistance 9 from the exchange battery "for a purposeto be pointed out more fully hereinafter. At its lower armature, rel-ay2 prepares a disconnect circuit 'to be subsequently traced; it preparesa circuit for relay 7 at its upper armature; and at its inner upper armature 1t dlscon-nect-s conductor 11 from battery by way of "contacts of similar relays in intervening-positions, contacts of sleeve CD1 oil-normal in the act of dialling the first digit, the off-normal contacts of calling device CD1, the upper contacts thereof, close a circuit through the upper contacts of relay 2, by way of conductor 13, for relay 7. Relay 7 operates and looks itself to ground at its upper armature, preparing a circuit for the calling-device-disconnect relay 6 at its lower armature. I v V As the calling device returns to its normal position, the control circuit extending over the two sides of the toll line TL in parallel from battery supplied thereto through the impulse contacts in the calling device CD1 and over conductor 11 by way of the inner upper armature of relay 2 is interrupted a number of times depending upon-the digit dialled. The automatic switching apparatus in the distant exchange responds in the manner explained in the icks patent referred to. As the operator continues to dial, each of the subsequent digits is transmitted in the manner of the first.

As soon as she has dialled the last digit, the operator again pushes the push button P1 momentarily, whereupon a circuit is closed at the lower contacts thereof for relay-'6 by way of contacts of relays 2 and 7. Relay 6 operates and closes a locking circuit for itself, opening its initial circuit. At its upper contacts relay 6 removes battery from conductor 12, whereupon relay 2 is released. When relay 2 releases, the control circuit is shifted back to battery through the resistance 8 and the lamp L1 becomes extinguished.

The conversation is carried on in the usual manner over the trunk line after the connection has been set up responsive to the trains of impulses sent over'the trunk line, andwhen the connectio-n. is, tobe takendown,;the operator withdraws the plug from multiple jack MJ-l whereuponsleeve, relay 4 falls back and opens the circuit of relays =6 and 7 at its upper armature, permitting both of these relays to release. The circuit tor the cut-off relayis opened at the same time and this relay falls back. At itsinner-upperarmature, relay -opens the control circuit over the toll line TL by conductor 11, permitting the connection through the automatic switches in the distant exchange to be released :in the usual manner.

Presenting double calling-desire connections or failing to make the usual busy test, and that the operator at position X operates the push button P2 to connect the calling device CD2 with the trunk iline TL. In this case, i

the relay'3 is energized from conductor 12 through 'bothof its windings, .but due to the reduced potential on conductor 12, the energization of the relay is not sufficient for its operation. This is because the battery potential from the upper contacts of relay 4 is supplied through resistance 9 and because relay 2 is held operated through the fairly low-resistance upper winding. The potential, however,

is sufiicient to hold relay 2 operated. The closure of the circuit through the two windings of relay 3 in series does not cause a substantial further lowering of the potential of conductor 12 owing to the fact that the two windings in series have a fairly high resistance. The operator at position X is notified of the failure of the attempt to connect the calling device with the trunk line by the continued unlighted condition of the lamp L2. Since relay 3 is not operated, the lower contacts of the push button P2 are ineffective to cause operation of relay 6, which if it occurred would remove the battery potential from conductor 12 and release relay 2.

After the operator at' position 1 has disconnected her calling device CDl from the toll line by reoperating push button P1, no calling device can intrude upon the connection as disconnect relay 6 maintains battery potential removed from conductor 12 until the connection is taken down.

What is claimed is:

1. In a telephone system, a line outgoing from a manual switchboard to an automatic switchboard, a switch-controlling calling device at said-manual switchboard common to said line and to other similar lines, a manual circuit-controlling device individual to said line, and means responsive to a momentary operation of said circuit controlling device for operatively associating the calling device with said line and for maintaining said calling device associatedwith said line after the circuit controlling device has been restored. i

2. In a telephone system, a line outgoing from a manual switchboard to an automatic switchboard, a switch-controlling calling device at said manual switchboard common to said line and to other similar lines, a manual circuit-controlling device individual to said line, means responsive to a momentary op-' eration of said circuit controlling device for operatively associating the calling device with said line, and means responsive to the said operation of .said circuit controlling device being repeated, after the calling device has been operated to control the switching apparatus at the automatic switchboard,

to disassociate said calling device from the line.

3. In a telephone system, a line outgoing from a manual switchboard to an automatic switchboard, a switch-controlling calling device at said manual switchboard common to said line and to other similar lines, a manual circuit-controlling device individual to said 'liiie,;nieans responsive "to a .momen'tary operation of said ClIGU1t C0I1t10ll1I1g device for operatively associatingithe calling dean" ,operators jpush. key flIldlVlCl'llal tojsaid l ne, means responsive to ,a; momentary op-;

eration ofysaid push key; for associatingsaid sender w th said line, .means respons ve to an operation of said sender to send impulses over said, line; for preparing to disassociate said :sender: and meansresponsive to a further momentary operatio1 1 of said push key for bringingabout the disassociation of the sender from-thei-line." R r -51 1 1. te phone y m,- a ine eu g in from a ,multi-positionmanual switchboard, a

calling device at each, position, of {said switchboard-common to. said'trunk line and to other similartr'unk lines, a -manual' push k y nfiliYifil ali'fio' an. trunk jl Lat each of said positions, means responsive to amon ary spe a i niof: t ei' an p s y at any position for assoc-'iating'the calling device at said position with said trunk line, and means for preventing the momentary operation of the manual push key individual to said line at a second position from associating a second calling device with said trunk line.

6. In a telephone system, a line outgoing from a multi-position manual switchboard, a calling device. at each position of said switchboard common to said line and to other similar lines, a manual push key individual to said line at each of said positions, means responsive to a momentary operation of the manual push key at any positionfor asso-o ciating the calling device at said position with said line, and means for preventing the disassociation of an associated calling device re.- sponsive to the operation of a push key at another position.

7. In a telephone system, a line outgoing from a manual switchboard, means-at the manual switchboard for extending a connection to said line, a calling device at said i switchboard commonto said line and to other similar lines, a manual push key individual to said lines, means responsive to a momentary operation of said manual push key after the said connection has been extended to said line for associating said calling device with said line, means responsive to a further momentary operation. of said; push key for disassociating said calling devicefrom said line and for rendering the associating means ineifective as long as the said connection re mains extended to said line.-

8. In a telephone system, a trunk line outgoing from a 'multi-positi'on manual switchboard, a calling device at each position of said switchboard,-a calling device connect ing relay individual to said trunk line at eachof said positions, and relay mechanism common to all of said connecting relays and arranged to control any one of them.

9. In a telephone system, a line outgoing from a multi-position' manual switchboard,

a plurality of calling devices, a plurality of relays, means for operating any one of said relays to connect the associated calling device to the line, and means common to all relays for preventing any-other're'lay from connecting the associated calling device to the line;

10; In a telephone system, a line outgoing from a manual switchboard to an automatic switchboard, a switch-controlling calling device at said manual switchboard common to said'lin'e and'to other similar lines, a manual circuit-controlling device individual to said line, and a self-locking relay responsive to amomentary operation of said circuit'controlling; device for operativelyassociating the calling device with-said line.

In witness whereof, hereunto subscribe my name this 31st day ofDecember, A. D;

. BROOKS.- 

